1. Field of the Invention
The present invention relates to apparatus and a method for orienting a tubular preform to a desired circumferential position before the preform is placed within a blow mold to be blown into a hollow article, such as a container. More particularly, the present invention relates to apparatus and a method for blow molding from a tubular preform a plastic container having a molded-in thread or outwardly extending ridge at the container neck, wherein the thread or ridge includes a gap or notch for permitting circumferential orientation of the preform to a desired position relative to the blow mold.
2. Description of the Related Art
Blow molded containers often include a closure that permits dispensing of a pourable product carried within the container. For example, a closure cap can contain a particular orientation of pouring holes, or a pouring spout, which is desirably oriented in a particular way relative to the container in order to facilitate pouring or dispensing of the product from within the container by a user. In that regard, if the container is of a specific shape to facilitate gripping by the user, such as an oval shape that can optionally include surface depressions or other formations to facilitate gripping or holding of the container, it is desirable that when the container is held for dispensing the product, the dispensing opening is properly positioned relative to the user's hand, so that the dispensing opening is on the distal side of the container, relative to the user, for ease of dispensing.
The notion of providing on a container or on a container preform specific structure to permit orientation of the bottle in a particular position has been suggested before. For example, in U.S. Pat. No. 4,212,841, which issued Jul. 15, 1980, to Edmond Michel, there is disclosed a container preform for blow molding, the preform including a false neck having at least one outwardly extending positioning lug to permit positioning the preform in a particular orientation. The false neck is essentially an appendage that is cut from the container after the completion of the blowing operation.
In U.S. Pat. No. 4,451,426, which issued May 29, 1984, to Jose Branchadell, there is disclosed another form of bottle preform having a false neck. The false neck includes a circular, toothed collar, the teeth of which are engagable by a gear wheel to permit the preform to be rotated by the gear wheel to a predetermined angular position. Again, the false neck is removed after the blowing operation.
The prior art structures described immediately above permit orientation of a preform for subsequent blowing, but because the structure that is used for preform orientation is subsequently removed from the final, blown article, it must be trimmed in a separate operation and then either discarded or recycled, which adds to the costs associated with producing such articles. Additionally, the prior art structures for orienting the preform are unduly complicated.
It is an object of the present invention to overcome the shortcomings of the prior art arrangements.